Earlier quoted context omitted.
News flash: A transaction requires a buyer and a seller. If you bought Bitcoin, someone else sold Bitcoin.
That doesn't account for an imbalance in the number of potential buyers and sellers. It's very easy to buy a house for $100 million. Go to your real estate agent and say "Here's a $100 million. Buy me a house." It is, however, considerably harder to sell a house for $100 million.
It's only easy to buy a house for $100M if you have $100M you can spare for house-buying. And then you only get to choose from the rather limited range of $100M houses that are available for sale.
Similarly, you only get to sell a house for $100M if you have a house that nice to sell. And then you only get to sell to the rather limited range of people willing to buy a house for $100M.
But perhaps I've misunderstood. If you happen to have $100M burning a hole in your pocket, it's easy to buy a house that would normally cost $1M with it, because most people with $1M houses will happily sell them for $100M. But the parallel to that is that if you happen to have a house that would normally cost $100M, it's easy to sell it for $1M. Which it would be.